runs fine in barrel but not on water, 1975

[Biglabsrule]

I have a 1975 Chrysler 10hp outboard that appears to run fine when i put it in a 55gallon drum but boggs down when i put it on a 14ft aluminum roweboat. Just got it, put new water pump in it, lower unit oil exc. but not sure what is wrong. Might the timming be off slightly and causing a problem. I checked the compression on the top cylinder and read a healthy 120ish, couldn't get to the lower one without pulling off the lower half of the cowl. any thoughts of where to go is greatly appriciated. thank you, Travis L. from upstate NY

 

[Bifflefan]

Re: runs fine in barrel but not on water, 1975

how much weight are you trying to push?
what prop is on it?
Whats the compression reading on the lower cylinder?
How long since it last good tune up?

 

[Biglabsrule]

Re: runs fine in barrel but not on water, 1975

not much weight just standard aluminum rowboat 48" beam maybe 250 lbs plus couple people... 600 total?

wasn't sure about the prop. it's some plastic three blade, doesn't look original but not sure how to measure it or what it should have

didn't check lower cylinders compression yet...

just bought the motor used and just got it running within the week, didn't change the points coils exc. just cleaned the surface of the points..
it runs pretty good, does have a slight noise though, was thinking about checking the timing next but not sure if that's the right thing to be checking.

 

[john from md]

Re: runs fine in barrel but not on water, 1975

Before doing anything else, you need to do a tuneup and check compression in number two. Anything else is all guesswork.

John